Heavy quark results from STAR
|
|
- Brandon Stewart
- 5 years ago
- Views:
Transcription
1 Eur. Phys. J. C (2009) 61: DOI /epjc/s Regular Article - Experimental Physics Heavy quark results from STAR Xin Dong a for the STAR Collaboration Lawrence Berkeley National Lab, Berkeley, CA 94720, USA Received: 12 September 2008 / Revised: 3 December 2008 / Published online: 21 February 2009 Springer-Verlag / Società Italiana di Fisica 2009 Abstract I report the most recent measurements on open heavy flavor production at RHIC on behalf of the STAR collaboration. The total charm production cross section in midrapidity at RHIC energy is found to approximately scale by number of binary collisions in d + Au, Cu + Cu and Au + Au collisions. The nuclear modification factor of nonphotonic electrons is strongly suppressed in central Au + Au collisions, suggesting substantial heavy quark energy loss at RHIC. The bottom decay contribution to non-photonic electrons was studied via the e h and e D 0 azimuthal angular correlations. The bottom contribution is found to be important at p T > 5GeV/c, and is consistent with the FONLL calculation within uncertainties. Charm production through gluon jet splitting was measured by studying the D ± contents in the fully reconstructed jets in p + p collisions. This rate is consistent with pqcd evaluation of gluon splitting into a pair of charm quarks and subsequent hadronization. PACS Dw Fc Ft p 1 Introduction Heavy quark production is believed to be a powerful test for pqcd calculations in elementary collisions. The theoretical predictions for heavy quark production cross section at high energies are extensively reported in [1, 2]. In heavy ion collisions, charm yields are expected to scale by N bin since most charm quark pairs are created in the initial hard processes. Due to their large mass, charm and bottom quark masses are not likely to be modified in the QCD medium. Hence heavy quark collectivity is a better probe of the early stage than light quarks, and thus indicates early thermalization of the lighter quarks. Measurements on open charm production also provide an important reference for charmonium production study, which is of great significance in searching a xdong@lbl.gov and quantifying the QGP. In this article, I will report the recent experimental results on open heavy quark production at RHIC collisions from the STAR experiment. 2 Recent open heavy quark measurements from STAR Table 2.1 lists the measurements made so far at STAR on the charm production spectra via various methods in different collision systems (shown as checkmarks). There are three independent methods: low p T D 0 reconstruction through the hadronic decay channel, non-photonic electrons, and heavy flavor decay muons. In the non-photonic electron approach, there are several independent analyses which involve three different subsystems: the Time Projection Chamber (TPC), the Time-Of-Flight (TOF) detector and the Electromagnetic Calorimeter (EMC) [3 5]. So far, all available results from these measurements are consistent with each other in each overlap area. The large coverage of the TPC would allow us to reconstruct charm mesons (like D 0 ) through its hadronic decay channels benefiting from the large statistics to overcome large combinatorial background. Figure 2.1 shows the unlike charge-sign Kπ invariant mass distributions after combinatorial background subtraction for D 0 + D 0 candidates at low p T (p T 3GeV/c) ind + Au, Au + Au and Cu + Cu minimum bias collisions [3, 4, 6]. The observed D 0 signal significances are 4 6σ in these systems, and the S/B ratios are around 1/3000 (Au + Au) 1/600 (d + Au). The semi-leptonic decay channel is an alternative approach to measure heavy quark production to reach higher p T and different kinematic regions. In STAR, the TOF and EMC detectors can help improve the e/h ratio by several orders of magnitude. One can refer to the publications [3 5] for technical details. Background electrons, which come from the inner detector conversions and light hadron electromagnetic decays (photonic electrons), were removed by the cut on small invariant mass of this electron and a partner
2 660 Eur. Phys. J. C (2009) 61: Table 2.1 Measurements made at STAR on the charm spectra via various methods in different collision systems D reconstruction non-photonic electrons low p T muons Sub-systems TPC TPC+TOF TPC TPC+EMC TPC+TOF p T coverage (GeV/c) p + p d + Au Cu + Cu Au + Au Fig. 2.1 Invariant mass distributions for D 0 + D 0 candidates from Kπ decay channelatlowp T in d + Au (upper left), Au + Au (upper right)andcu+ Cu (lower) minimum bias collisions in snn = 200 GeV positron. The partner finding efficiency was estimated from the Monte Carlo simulations, which is 50% at low p T and increases to 80% at high p T. Background subtracted electron (non-photonic electron) spectra from TPC+TOF and TPC+EMC combinations in various collision systems are shown in Fig By combining the TOF and TPC, one can identify muons at 0.17 <p T < 0.25 GeV/c in Au + Au collisions [4]. Low
3 Eur. Phys. J. C (2009) 61: Fig. 2.3 The extract charm cross sections at mid-rapidity from various collision system compared with the NLO pqcd calculations. Statistical and systematical errors are depicted by the black lines and green bars, respectively Fig. 2.2 Upper: D 0, non-photonic electron and heavy flavor decay μ transverse momentum spectra from A + A collisions at low p T. Lower: Non-photonic electron transverse momentum spectra from various systems at high p T p T muons are interesting because the yield of those muons is sensitive to the total charm cross section, and doesn t change much with the charm spectrum shape [7]. Therefore, the muon measurement will have a significant impact on the charm total cross section measurement. By statistical subtraction of the muons from light hadron weak decays, one obtains the muon yield which is expected from the heavy flavor decays. The data points in Au + Au collisions are shown in Fig. 2.2 upper plot. To take advantage of all available measurements, we perform combined fits to all available data points on D 0, μ, and non-photonic electrons in each collision system [3, 4] (fitto D 0 data points only in Cu + Cu collisions). The results from d + Au, Cu + Cu, Au + Au minimum bias, and Au + Au central collisions are shown in Fig The results show that the total charm cross section scales with number of binary collisions from d + Au collisions to Au + Au central collisions with the current experimental uncertainty. A pre- cision measurement on the total charm cross section in various collision systems is important because the total charm cross section is an input in the calculation of charmonium production yields through coalescence process, and the charmonium suppression or enhancement could be a QGP signature in heavy ion collisions. The cross section results are also compared with the recent NLO pqcd calculation [1, 2] on the total charm cross section on that figure. The finding from the NLO calculations is that the theoretical uncertainties on the charm cross section are quite large. Within the usual variations of the calculation, including charm quark mass, factorization and renormalization scales, the total calculated cross section and the experimentally measured one are consistent with each other. The particle transverse momentum spectrum in the low p T region can often be fit to the Blast-Wave (BW) model and depict the flow and freeze-out characteristics. To study whether charm hadrons have similar radial flow to light hadrons, the data points of the nuclear modification factors (R AA, d + Au data points used as the baseline) for μ and non-photonic electrons, shown in Fig. 2.4 upper plot, are compared with those curves for the expected R AA from a BW model using the freeze-out parameters for light hadrons (BW3 in Fig. 2.4 upper plot) and multi-strange hadrons (BW2) [4]. These two curves miss the data points by a large distance, while the best BW fit to the D 0, μ and non-photonic electron data points show significant differences from both these curves for p T > 1GeV/c, which suggests that the charm hadron freeze-out and flow are different from light hadrons. The χ 2 scan in a 2-dimensional T fo (freeze-out temperature), β t (mean transverse velocity) space shows little sensitivity to the freeze-out temperature, but disfavors large radial flow. These findings, together with the observation of large charm elliptic flow, are consistent with the recent prediction from hydrodynamics: elliptic flow is built up at partonic stage, and radial flow dominantly
4 662 Eur. Phys. J. C (2009) 61: Fig. 2.4 Upper: Nuclear modification factor (R AuAu/dAu )forμ and non-photonic electrons in 0 12% Au + Au collisions. The data points are compared with the calculations from the BW models with several different sets of freeze-out parameters at low p T, and energy loss models at high p T. Lower: IntegratedR AA (p T > 3GeV/c) of non-photonic electrons from different centralities in Au + Au collisions and Cu + Cu minimum bias collision comes from hadronic scattering at a later stage where charm hadron may have already decoupled from the system [4]. Figure 2.4 upper plot also shows at high p T, the nonphotonic electron R AA is strongly suppressed, indicating the heavy quark may also lose significant amount of energy when traversing through the medium. The results from TPC+TOF and TPC+EMC measurements are consistent [4, 5]. Recent non-photonic electron measurements in Cu + Cu collisions show that significant suppression also exists in Cu + Cu system. Figure 2.4 lower plot shows the integrated R AA (p T > 3GeV/c) of non-photonic electrons vs. number of participants in various systems. The preliminary measurement in Cu + Cu shows the R AA suppression of non-photonic electron follows the same N part dependence as the Au + Au data. The discovery of the strong suppression in non-photonic electron R AA challenges theorists to revisit the energy loss mechanisms. On the experimental side of the non-photonic electron research, the main hindrance is the difficulty to distinguish the contributions of charm and bottom separately. On the theory side, the FONLL calculation of the p T spectrum predicts the crossing point between electrons coming from charm and those from bottom decays can happen anywhere between 3 10 GeV/c [1, 2]. One must therefore rely on additional measurements to pin this down. STAR tried a couple of approaches to extract the bottom contribution via non-photonic electron triggered correlation analyses. The first one is by measuring the azimuthal angular correlations between non-photonic electrons and charged hadrons in p + p collisions [8, 9]. Due to the larger mass of bottom hadrons, the near-side correlation function width is expected to be larger in the semi-leptonic decay of a B meson compared to a D meson. We obtained the distributions for charm meson decay and bottom meson decay based on Monte Carlo simulation (PYTHIA), and then simultaneously fit the experimental correlation function with these two distributions and obtain the relative contribution of bottom decay to the non-photonic electron yields as a function of p T (2.0 <p T < 9.0 GeV/c). For technical details of this analysis, please refer to Ref. [8, 9]. The other one is by measuring the azimuthal angular correlations between non-photonic electrons and D 0 in p + p collisions [10]. MC simulations (PYTHIA and MC@NLO) predict the e D 0 correlation for electrons from D meson decays will dominantly distribute in the away side, while that for electrons from B meson decays will dominantly distribute in the near side (there is still a small amount of away side contribution). In the Barrel EMC tower triggered sample, D 0 reconstructed through K π + channel is significantly enhanced compared to the minimum bias data sample. The signal-to-background ratio was improved by a factor of 100 compared to that obtained in d + Au minimum bias collisions. The azimuthal correlation function of e D 0 (and e + D 0 ) was fit to the sum of two components, and one can extract the relative bottom contributions to the electron yields. The relative contribution of electrons from B meson decays to the non-photonic electron yields (R B ) estimated by the two approaches is shown in Fig. 2.5, compared with the FONLL predictions. We can see R B increases with p T and it becomes comparable to the contribution from D meson decay around 5.0 GeV/c. Our result is consistent with the FONLL calculation within the uncertainties. In the e D 0 analysis, MC calculations show the near side correlation is essentially from B meson decays, and the gluon splitting process for D production is negligible. The multiplicity of heavy quark pairs in gluon jets is calculable in pqcd, and the leading nonperturbative correction is believed to be small [11]. Thus, experimentally measuring the charm yields from gluon jet splitting becomes important.
5 Eur. Phys. J. C (2009) 61: Fig. 2.5 Transverse momentum dependence for the relative contribution of electron from B meson to the non-photonic electron yields from e h and e D 0 azimuthal angular correlation analysis. The curves are FONLL calculations The measurement is done by measuring the D ± yields in the reconstructed jets. D ± was reconstructed through the standard method of searching for the decay sequence D + D 0 π +, D 0 K π + (and its charge conjugate channel) by plotting the invariant mass difference M = M(K π ± π ± ) M(K π ± ). Jets were reconstructed using a mid-point cone algorithm, and the jet reconstruction is described in Ref. [12]. Then we correlated the D ± with the reconstructed jets, and calculated the fragmentation variable z p L (K π ± π ± )/E jet for the near side signal candidates, which is shown in Fig. 2.6 upper plot. The uncertainties represented by bars are statistical and the brackets indicate the contribution caused by combinatorial background subtraction. No correction were made in this plot for trigger and reconstruction efficiency. The MC data shown in Fig. 2.6 upper plot were generated using PYTHIA with only direct charm flavor creation processes (gg c c, and q q c c). The simulated data were analyzed in the same way as the real data and were normalized using the total charm production cross section measured by STAR [3]. The high z data points are well reproduced by the simulation with direct flavor creation processes, while the excess in the low z region is expected to originate from production processes that are not included in the simulation, such as gluon splitting. After efficiency and acceptance corrections, we obtain N(D ± )/N(jet) = ± ± for 0.2 <z<0.5 with mean jet energy E T =11.5 GeV. To get the ratio of gluon splitting into charm pairs R g c c, one needs to correct for the gluon jet fraction, the charm quark to D + fragmentation fraction, and the z coverage. The final gluon splitting rate data point from STAR, together with measurements from other experiments [14, 15]areshowninFig.2.6 lower plot. The datum point is consistent with pqcd evaluation Fig. 2.6 Upper: D in jet fragmentation variable z distributions from Barrel JP2 data set compared with the full MC simulation with only direct flavor creation process. The excess in low z region is expected from higher order processes. Lower: Gluon splitting rate to charm pairs as a function of the gluon jet energy. Measurements from STAR, UA1, and CDF collaborations are compared with pqcd calculations of gluon splitting into a pair of charm quarks and subsequent hadronization into D ± mesons [11]. To gain insight in the production mechanism of charmed hadrons at RHIC, we use the measured jet differential cross section [13] and the gluon splitting rate [11] to estimate the contribution of gluon jet production to the total charm production cross section. We find that for p T > 2GeV/c, charm production in gluon jets is more than one order of magnitude smaller than the total charm cross section [1, 2]. Hence the charm content in jets at RHIC energies has a small contribution from gluon splitting and is dominated by jets initiated by charm quarks. 3 Summary and outlook The STAR detector is unique to perform multi-approach measurements on heavy quark production in midrapidity at RHIC. STAR has made extensive measurements on open
6 664 Eur. Phys. J. C (2009) 61: charm hadron reconstruction through its hadronic decay channel, non-photonic electrons, heavy quark decay muons and heavy quark triggered correlations. So far, the conclusions achieved still have large uncertainties. To quantify the medium properties and Equation-Of-State, precision measurements on open heavy quark production are called for. Topological reconstruction of identified open heavy quark hadrons is essential in this direction. So the current subdetector upgrade plans in pipe for the STAR detector are very important to this goal. The Heavy Flavor Tracker proposal [16] will allow us to reconstruct the secondary vertices of open charm decays with much lower background. The ongoing Time-Of-Flight project will improve the hadron particle identification capability significantly; hence improve the signal-to-background ratio for charm hadron reconstruction. References 1. M. Cacciari et al., Phys. Rev. Lett. 95, (2005) 2. R. Vogt, arxiv: J. Adams et al., Phys. Rev. Lett. 94, (2005) 4. B.I. Abelev et al., arxiv: B.I. Abelev et al., Phys. Rev. Lett. 98, (2007) 6. A. Shabetai et al., in QM08 Proceedings 7. H. Liu et al., Phys. Lett. B 639, 441 (2006) 8. X. Lin et al. (STAR Collaboration), J. Phys. G 34, S821 (2007) 9. G. Wang et al. (STAR Collaboration), in QM08 Proceedings 10. A. Mischke et al. (STAR Collaboration), These Proceedings 11. A.H. Mueller, P. Nason, Phys. Lett. B 157, 226 (1985) 12. B.I. Abelev et al., Phys. Rev. Lett. 100, (2008) 13. B.I. Abelev et al., Phys. Rev. Lett. 97, (2006) 14. C. Albajar et al., Phys. Lett. B 244, 566 (1990) 15. F. Abe et al., Phys. Rev. Lett. 64, 348 (1990) 16. STAR HFT Collaboration, STAR HFT Proposal
The measurement of non-photonic electrons in STAR
The measurement of non-photonic electrons in STAR Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Břehová 7, 11519, Prague 1, Czech Republic E-mail: olga.hajkova@fjfi.cvut.cz
More informationPHENIX measurements of bottom and charm quark production
Journal of Physics: Conference Series PAPER OPEN ACCESS PHENIX measurements of bottom and charm quark production To cite this article: Timothy Rinn and PHENIX Collaboration 2018 J. Phys.: Conf. Ser. 1070
More informationSusanna Costanza. (Università degli Studi di Pavia & INFN Pavia) on behalf of the ALICE Collaboration
(Università degli Studi di Pavia & INFN Pavia) on behalf of the ALICE Collaboration 102 Congresso della Società Italiana di Fisica Padova, 26-30 settembre 2016 Outline Heavy flavour physics in ALICE The
More informationHeavy-flavour meson production at RHIC
Heavy-flavour meson production at RHIC André Mischke ERC-Starting Independent Research Group QGP - Utrecht 1 Outline Introduction - heavy-flavour production and energy loss in QCD matter Total charm production
More informationarxiv: v1 [nucl-ex] 12 May 2008
1 Highlights from PHENIX - II arxiv:0805.1636v1 [nucl-ex] 12 May 2008 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Terry C. Awes (for the PHENIX Collaboration ) Oak
More informationOpen heavy-flavour production in pp, p Pb and Pb Pb collisions in ALICE
Open heavy-flavour production in pp, p Pb and Pb Pb collisions in ALICE (INFN, Bologna) on behalf of the ALICE Collaboration Bormio Winter Meeting 26/01/2018 Why open heavy flavour in ALICE? Heavy-flavour
More informationLongitudinal Double Spin Asymmetry in Inclusive Jet Production at STAR
Longitudinal Double Spin Asymmetry in Inclusive Jet Production at STAR Katarzyna Kowalik for the STAR Collaboration Lawrence Berkeley National Laboratory, Berkeley, California 94720 Abstract. This contribution
More informationJet quenching in PbPb collisions in CMS
Jet quenching in PbPb collisions in CMS Bolek Wyslouch École Polytechnique Massachusetts Institute of Technology arxiv:1102.1957 Orsay, February 18, 2011 1 Heavy Ions at the LHC Huge energy jump from RHIC:
More informationHeavy-flavor production in pp and Pb Pb collisions at LHC with ALICE
Heavy-flavor production in pp and Pb Pb collisions at LHC with ALICE Kai Schweda 1 on behalf of the ALICE Collaboration Physikalisches Institut der Universität Heidelberg, Philosophenweg 12, D-69120 Heidelberg,
More informationSelected highlights from the STAR experiment at RHIC
Selected highlights from the STAR experiment at RHIC Sonia Kabana for the STAR Collaboration Laboratoire de Physique Subatomique et des technologies associees (SUBATECH) and University of Nantes, France
More informationShingo Sakai Univ. of California, Los Angeles
Shingo Sakai Univ. of California, Los Angeles Non-photonic e result in AuAu b/c separation in non-photonic electron by electron-hadron correlations @ pp Bottom production Discuss heavy flavor energy loss
More informationHeavy Flavor Results from STAR
Heavy Flavor Results from STAR Wei Xie for STAR Collaboration (PURDUE University, West Lafayette) Open Heavy Flavor Production D meson direct measurement Non-photonic electron Heavy Quarkonia Production
More informationLepton and Charm Measurements in the First Two Years of RHIC: An Experimental Overview
Lepton and Charm Measurements in the First Two Years of RHIC: An Experimental Overview Ralf Averbeck State University of New York at Stony Brook INT/RHIC Winter Workshop, Seattle, December 13-15, 2002
More informationPhoton and neutral meson production in pp and PbPb collisions at ALICE
Photon and neutral meson production in pp and PbPb collisions at ALICE Dieter Roehrich University of Bergen, Norway for the ALICE Collaboration Nuclear collisions at the LHC Photons as a probe for the
More informationSTAR Open Heavy Flavor Measurements
STAR Open Heavy Flavor Measurements Xin Dong Lawrence Berkeley National Laboratory Physics Goals Mass Dependence of DE Au+Au@200GeV, 0-5% Brownian motion CUJET drag fluctuations PRL 108 (2012) 022301 Diffusion
More informationHeavy flavour production at RHIC and LHC
Heavy flavour production at RHIC and LHC Gian Michele Innocenti 1, 1 Massachusetts Institute of Technology Abstract. In this proceedings, I present selected experimental results on heavy-flavour production
More informationAzimuthal anisotropy of the identified charged hadrons in Au+Au collisions at S NN. = GeV at RHIC
Journal of Physics: Conference Series PAPER OPEN ACCESS Azimuthal anisotropy of the identified charged hadrons in Au+Au collisions at S NN = 39-200 GeV at RHIC To cite this article: S S Vdovkina 2017 J.
More informationMeasurement of light mesons at RHIC by the PHENIX experiment
Eur. Phys. J. C (2009) 61: 835 840 DOI 10.1140/epjc/s10052-009-0879-4 Regular Article - Experimental Physics Measurement of light mesons at RHIC by the PHENIX experiment M. Naglis a for the PHENIX Collaboration
More informationInclusive spectrum of charged jets in central Au+Au collisions at s NN = 200 GeV by STAR
Inclusive spectrum of charged jets in central Au+Au collisions at s NN = 200 GeV by SAR Nuclear Physics Institute, Academy of Sciencis of Czech Republic, Na ruhlarce 39/64, 180 86 Prague, Czech Republic
More informationSelected highlights from RHIC
Selected highlights from RHIC Sonia Kabana Laboratoire de Physique Subatomique et des technologies associees (SUBATECH) and University of Nantes, France QGP-France workshop Etretat, France, 9-11 September
More informationarxiv: v1 [hep-ex] 9 Jan 2019
Quarkonium production as a function of charged-particle multiplicity in pp and p Pb collisions measured by ALICE at the LHC arxiv:1901.02627v1 [hep-ex] 9 Jan 2019 Discipline of Physics, School of Basic
More informationHeavy Ion Results from the ALICE Experiment
Heavy Ion Results from the ALICE Experiment Johannes P. Wessels on behalf of the ALICE Collaboration Institute for uclear Physics University of Münster D-89 Münster, Germany and CER, CH- Geneva, Switzerland
More information51st Rencontres de Moriond QCD and High Energy Interactions La Thiule, IT 25/Mar/2016. Manuel Calderón de la Barca Sánchez
51st Rencontres de Moriond QCD and High Energy Interactions La Thiule, IT 25/Mar/2016 Manuel Calderón de la Barca Sánchez Heavy Flavors in Heavy Ions Heavy quarks produced early: initial hard parton collision
More informationarxiv: v1 [nucl-ex] 7 Jan 2019
Open Heavy Flavour: Experimental summary arxiv:9.95v [nucl-ex] 7 Jan 9 Deepa homas he University of exas at Austin E-mail: deepa.thomas@cern.ch In this paper I will review a few of the latest experimental
More informationCharm production at RHIC
1 Charm production at RHIC Charm 2007 Conference Cornell University, Ithaca, NY 5 August 2007 2 The Quark Gluon Plasma T c Early universe quark-gluon plasma LHC RHIC Tri-critical point? Quark deconfinement
More informationPerspectives for the measurement of beauty production via semileptonic decays in ALICE
Perspectives for the measurement of beauty production via semileptonic decays in ALICE Rosario Turrisi INFN Padova (Italy for the ALICE collaboration Contents Motivation: energy loss ALICE detector highlights
More informationSoft physics results from the PHENIX experiment
Prog. Theor. Exp. Phys. 2015, 03A104 (15 pages) DOI: 10.1093/ptep/ptu069 PHYSICS at PHENIX, 15 years of discoveries Soft physics results from the PHENIX experiment ShinIchi Esumi, Institute of Physics,
More informationLHC Heavy Ion Physics Lecture 5: Jets, W, Z, photons
LHC Heavy Ion Physics Lecture 5: Jets, W, Z, photons HUGS 2015 Bolek Wyslouch Techniques to study the plasma Radiation of hadrons Azimuthal asymmetry and radial expansion Energy loss by quarks, gluons
More informationarxiv: v1 [hep-ex] 14 Jan 2016
Nuclear Physics A Nuclear Physics A (28) 5 www.elsevier.com/locate/procedia arxiv:6.352v [hep-ex] 4 Jan 26 Measurements of heavy-flavour nuclear modification factor and elliptic flow in Pb Pb collisions
More informationJet Physics with ALICE
Jet Physics with ALICE Oliver Busch for the ALICE collaboration Oliver Busch Tsukuba 2014 /03/13 1 Outline introduction results from pp jets in heavy-ion collisions results from Pb-Pb collisions jets in
More informationQuarkonia and Open Heavy Flavor Results from CMS
Quarkonia and Open Heavy Flavor Results from CMS For the CMS collaboration Heavy Quark Physics in Heavy-Ion Collisions ECT*, Trento, Italy 16-20 March, 2015 Relativistic Heavy Ion Collisions Trying to
More informationsnn = 200 GeV Au+Au collisions with the STAR experiment
Measurements of open charm production and flow in snn = GeV Au+Au collisions with the STAR experiment at RHIC Spyridon Margetis 1, for the STAR Collaboration 1 Department of Physics, Kent State University,
More informationarxiv: v1 [nucl-ex] 29 Feb 2012
Measurement of the nuclear modification factor of electrons from heavy-flavour hadron decays in Pb Pb collisions at s NN =.76 ev with ALICE at the LHC arxiv:.65v [nucl-ex] 9 Feb Markus Fasel for the ALICE
More informationarxiv: v2 [nucl-ex] 17 Sep 2014
Heavy-flavour production and multiplicity dependence in pp and p Pb collisions with ALICE. Elena Bruna arxiv:9.675v [nucl-ex] 7 Sep On behalf of the ALICE Collaboration, IF orino Via P. Giuria, 5 orino,
More informationOpen-charm and J/ψ production at the ALICE experiment
Open-charm and J/ψ production at the ALICE experiment Pietro Cortese Università del Piemonte Orientale and INFN Alessandria, Italy on behalf of the ALICE Collaboration Purdue University, Jan. 6, 2011 Pietro
More informationAssessment of triangular flow in jet background fluctuations for Au+Au collisions First look at dijet imbalance (A J )
Assessment of triangular flow in jet background fluctuations for Au+Au collisions First look at dijet imbalance (A J ) Wayne State REU 2012 Research Advisor: Joern Putschke Research Undergraduate: Joshua
More informationarxiv: v1 [hep-ex] 18 May 2015
ALICE summary of light flavour results at intermediate and high p arxiv:55.477v [hep-ex] 8 May 5 uva Richert, on behalf of the ALICE collaboration Lund University, Department of Physics, Div. of Particle
More informationQCD at CDF. Régis Lefèvre IFAE Barcelona On behalf of the CDF Collaboration
QCD at CDF Régis Lefèvre IFAE Barcelona On behalf of the CDF Collaboration Jet Inclusive Cross-Section Underlying event studies Jet Shapes Specific processes _ W+Jets, γ + γ, γ + b/c, b-jet / bb jet Diffraction
More informationConference Report Mailing address: CMS CERN, CH-1211 GENEVA 23, Switzerland
CMS CR - he Compact Muon Solenoid Experiment Conference Report Mailing address: CMS CERN, CH- GENEVA 3, Switzerland 8/5/6 Charmonium production measured in and pp collisions by CMS arxiv:7.5v [nucl-ex]
More informationPoS(EPS-HEP 2009)317. Heavy flavour production at LHC
and André MISCHKE. ERC-Starting Independent Research Group, Faculty of Science, Utrecht University, Princetonplein 5, 3584CC Utrecht, The Netherlands. E-mail: a.grelli@uu.nl, a.mischke@uu.nl The Large
More informationMeasurement of D-meson production in p-pb collisions with the ALICE detector
Journal of Physics: Conference Series OPEN ACCESS Measurement of D-meson production in p-pb collisions with the ALICE detector Related content - he ALICE Collaboration - he ALICE Collaboration - he ALICE
More informationJet Results in pp and Pb-Pb Collisions at ALICE
Jet Results in pp and Pb-Pb Collisions at ALICE Oliver Busch for the ALICE Collaboration Motivation Jet reconstruction in ALICE Jets in pp Jets in Pb-Pb Hadron triggered recoil jets Motivation Jets originate
More informationSummary on high p T probes
Eur. Phys. J. C (2009) 61: 741 745 DOI 10.1140/epjc/s10052-009-0913-6 Regular Article - Experimental Physics Summary on high p T probes Saskia Mioduszewski a Cyclotron Institute, Texas A&M University,
More information+ High p T with ATLAS and CMS in Heavy-Ion 2.76TeV
+ High p T with ATLAS and CMS in Heavy-Ion Collisions @ 2.76TeV Lamia Benhabib On behalf of ATLAS and CMS HCP 2011, Paris lamia.benhabib@llr.in2p3.fr +Outlook Introduction : hard probes Strongly interacting
More informationarxiv:hep-ex/ v1 16 Jan 2004
Heavy Flavor Production at the Tevatron Chunhui Chen (Representing the CF and Ø Collaboration) arxiv:hepex/4v 6 Jan 4 epartment of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 94,
More informationPhysics at Hadron Colliders
Physics at Hadron Colliders Part 2 Standard Model Physics Test of Quantum Chromodynamics - Jet production - W/Z production - Production of Top quarks Precision measurements -W mass - Top-quark mass QCD
More informationLawrence Berkeley National Laboratory Lawrence Berkeley National Laboratory
Lawrence Berkeley National Laboratory Lawrence Berkeley National Laboratory Title High pt inclusive charged hadron spectra from Au+Au collisions at Sqrt(s_NN)=00 Gev Permalink https://escholarship.org/uc/item/3jp4v8vd
More informationOverview of ALICE results on azimuthal correlations using neutral- and heavy-flavor triggers
Journal of Physics: Conference Series PAPER OPEN ACCESS Overview of ALICE results on azimuthal correlations using neutral- and heavy-flavor triggers o cite this article: Sona Pochybova and ALICE Collaboration
More informationDirect Hadronic Reconstruction of D ± Mesons at STAR
Direct Hadronic Reconstruction of D ± Mesons at STAR Nathan Joseph Department of Physics and Astronomy, Wayne State University, Detroit, MI September 2, 2009 1 Introduction: Quark-Gluon Plasma The theory
More informationProspective of gamma hadron correlation. study in CMS experiment
Prospective of gamma hadron correlation. study in CMS experiment Yeonju Go (Korea University) for the CMS collaboration 5-6 Dec. 2014 HIM meeting Contents Physics Motivation Direct gamma-hadron correlation
More informationStrange Hadron Production from STAR Fixed-Target Program
Strange Hadron Production from STAR Fixed-Target Program (for the STAR Collaboration) Department of Engineering Physics, Tsinghua University, Beijing 84, China E-mail: musman_mughal@yahoo.com We report
More informationResults with Hard Probes High p T Particle & Jet Suppression from RHIC to LHC
Results with Hard Probes High p T Particle & Jet Suppression from RHIC to LHC PHENIX! AGS! RHIC! STAR! Cover 3 decades of energy in center-of-mass s NN = 2.76 TeV 5.5 TeV (2015) CMS LHC! s NN = 5-200 GeV
More informationDi muons and the detection of J/psi, Upsilon and Z 0 Jets and the phenomenon of jet quenching
collisions in CMS Bolek Wyslouch École Polytechnique Massachusetts Institute of Technology on behalf of CMS Collaboration CERN, December 2, 2010 1 Heavy Ions at the LHC Huge energy jump from RHIC: factor
More informationIdentified charged hadron production in pp, p Pb and Pb Pb collisions at LHC energies with ALICE
EPJ Web of Conferences 95, 04075 (2015) DOI: 10.1051/ epjconf/ 20159504075 C Owned by the authors, published by EDP Sciences, 2015 Identified charged hadron production in pp, p Pb and Pb Pb collisions
More informationMeasurements of the dilepton continuum in ALICE. Christoph Baumann Resonance Workshop, Austin
Measurements of the dilepton continuum in ALICE Christoph Baumann 07.03.2012 Resonance Workshop, Austin ALICE Central Detectors: Inner Tracking System Time Projection Chamber Time-of-Flight Transition
More informationMeasurement of Quenched Energy Flow for Dijets in PbPb collisions with CMS
Measurement of Quenched Energy Flow for Dijets in PbPb collisions with CMS For the CMS Collaboration NPA Seminar Yale, USA 15 October, 2015 Relativistic Heavy Ion Collisions Trying to answer two important
More informationarxiv:nucl-ex/ v1 21 Dec 2004
φ meson production in d + Au collisions at s NN = 00 GeV arxiv:nucl-ex/041048v1 1 Dec 004 1. Introduction Dipali Pal for the PHENIX collaboration Department of Physics & Astronomy, Vanderbilt University,
More informationarxiv: v1 [nucl-ex] 10 Feb 2012
Cent. Eur. J. Phys. 1-5 Author version Central European Journal of Physics Highlights of the Beam Energy Scan from STAR Review Article arxiv:10.389v1 [nucl-ex] 10 Feb 01 A. Schmah for the STAR Collaboration
More informationCharm reconstruction using a micro-vertexing technique with the STAR Silicon Vertex Detectors
Charm reconstruction using a micro-vertexing technique with the SAR Silicon Vertex Detectors Kent State University, Kent, Ohio 444, USA E-mail: bouchet@rcf.bnl.rhic.gov Due to their production at the early
More informationJet quenching in heavy-ion collisions at the LHC. Marta Verweij CERN
Jet quenching in heavy-ion collisions at the LHC Marta Verweij CERN EPFL Seminar May. 2, 2016 Thousands of particles are produced in one heavy ion collision Marta Verweij 2 Heavy ion collision Marta Verweij
More informationCorrelations of Electrons from Heavy Flavor Decay with Hadrons in Au+Au and p+p Collisions arxiv: v1 [nucl-ex] 11 Jul 2011
Correlations of Electrons from Heavy Flavor Decay with Hadrons in and Collisions arxiv:7.v [nucl-ex] Jul Anne M. Sickles, for the PHENIX Collaboration Brookhaven National Laboratory, Upton, NY E-mail:
More informationarxiv: v1 [hep-ex] 18 Jan 2016
Jet measurements in pp, p Pb and Pb Pb collisions with ALICE at the LHC arxiv:6.446v [hep-ex] 8 Jan 6 Centre for Astroparticle Physics and Space Science, Bose Institute, Kolkata, 79 (INDIA) E-mail: sprasad@cern.ch
More informationMULTI-CHANNEL MEASUREMENTS OF LIGHT VECTOR MESONS AT PHENIX
International Journal of Modern Physics E Vol. 16, Nos. 7 & 8 (2007) 2154 2159 c World Scientific Publishing Company MULTI-CHANNEL MEASUREMENTS OF LIGHT VECTOR MESONS AT PHENIX KENTA SHIGAKI [PHENIX Collaboration]
More information& Λ Production in ALICE
Journal of Physics: Conference eries OPEN ACCE Related content K & Λ Production in ALICE - trangeness production in ALICE Domenico Elia and the ALICE Collaboration o cite this article: Luke Hanratty and
More informationD + analysis in pp collisions
D + analysis in pp collisions Giacomo Ortona INFN Torino Junior s Day (CERN) - 2010-11-11 Junior s Day (CERN) - 2010-11-11 2010-11-11 1 / 22 Outline 1 Physics Motivation 2 Invariant Mass Analysis 3 Cuts
More informationMeasurement of Electrons from Beauty-Hadron Decays in p-pb Collision at snn = 5.02 TeV with ALICE at the LHC
Measurement of Electrons from Beauty-Hadron Decays in p-pb Collision at snn = 5.02 ev with ALICE at the LHC Minjung Kim, Inha University Advised by: Prof. MinJung Kweon, Prof. Jin-Hee Yoon Dec 5 th 2014,
More informationJet Physics at ALICE. Oliver Busch. University of Tsukuba Heidelberg University
Jet Physics at ALICE Oliver Busch University of Tsukuba Heidelberg University 1 2 Outline Introduction Results from pp collisions Identified jet fragmentation in pp Jets in heavy-ion collisions Jet shapes
More informationSmall Collision Systems at RHIC
EPJ Web of Conferences 7, (8) SQM 7 https://doi.org/.5/epjconf/87 Small Collision Systems at RHIC Norbert Novitzky, Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 79, USA
More informationPreparations for the ATLAS Heavy Ion Physics Program at the LHC. Deepak Kar IKTP, TU Dresden On behalf of the ATLAS Collaboration
Preparations for the ATLAS Heavy Ion Physics Program at the LHC Deepak Kar IKTP, TU Dresden On behalf of the ATLAS Collaboration 1 QCD Hadronic phase: Bound states of quark and gluon pp collisions Heavy
More informationet Experiments at LHC
et Experiments at LHC (as opposed to Jet Physics at RHIC ) JET Collaboration Symposium Montreal June 2015 Heavy-ion jet results at LHC Dijet asymmetries Observation of a Centrality-Dependent Dijet Asymmetry
More informationCharged jets in p Pb collisions measured with the ALICE detector
Charged jets in p Pb collisions measured with the ALICE detector (CERN) for the ALICE collaboration (25.03.2015) Rencontres de Moriond, QCD and High Energy Interactions, La Thuile Motivation for p Pb Study
More informationPion, Kaon, and (Anti-) Proton Production in Au+Au Collisions at s = 62.4 GeV
Pion, Kaon, and (Anti-) Proton Production in AuAu Collisions at s = 6.4 GeV NN Ming Shao 1, for the STAR Collaboration 1 University of Science & Technology of China, Anhui 3007, China Brookhaven National
More informationarxiv: v1 [nucl-ex] 10 Jan 2009
Hard Probes 2008 Conference Proceedings. June 9th, 2008. Illa da Toxa, Spain Two-particle Direct Photon-Jet Correlation Measurements in PHENIX J. Frantz a for the PHENIX Collaboration a State University
More informationRecent STAR Jet Results of the High-Energy Spin Physics Program at RHIC
Recent STAR Jet Results of the High-Energy Spin Physics Program at RHIC Daniel L. Olvitt Jr. Temple University E-mail: daniel.olvitt@temple.edu The production of jets from polarized proton+proton collisions
More informationThe first Z boson measurement in the dimuon channel in PbPb collisions at s = 2.76 TeV at CMS
The first Z boson measurement in the dimuon channel in PbPb collisions at s = 2.76 TeV at CMS Lamia Benhabib On behalf of CMS collaboration We present the first measurement of Z bosons in the di-muon channel
More informationThe Quark-Gluon Plasma and the ALICE Experiment
The Quark-Gluon Plasma and the ALICE Experiment David Evans The University of Birmingham IoP Nuclear Physics Conference 7 th April 2009 David Evans IoP Nuclear Physics Conference 2009 1 Outline of Talk
More informationConference Report Mailing address: CMS CERN, CH-1211 GENEVA 23, Switzerland
Available on the CMS information server CMS CR 212/178 The Compact Muon Solenoid Experiment Conference Report Mailing address: CMS CERN, CH211 GENEVA 23, Switzerland 212//9 Measurement of isolated photon
More informationRecent transverse spin results from STAR
1 STAR! Recent transverse spin results from STAR Qinghua Xu, Shandong University PanSpin215, Taipei, October 8, 215! Outline 2 Introduction Single spin asymmetries in the forward region Mid-rapidity hadron-jet
More informationMeasurement of the jet production properties at the LHC with the ATLAS Detector
Measurement of the jet production properties at the LHC with the ALAS Detector Stanislav okar Comenius University, Bratislava On behalf of the ALAS collaboration Different features of the jet production
More informationQuarkonium production measurement in Pb-Pb collisions at forward and mid rapidity with the ALICE experiment
Quarkonium production measurement in Pb-Pb collisions at forward and mid rapidity with the ALICE experiment Lizardo Valencia Palomo Institut de Physique Nucléaire d Orsay (CNRS-IN2P3, Université Paris-Sud
More informationZ 0 /γ +Jet via electron decay mode at s = 7TeV in
PRAMANA c Indian Academy of Sciences Vol. 86, No. 2 journal of February 2016 physics pp. 487 491 Z 0 /γ +Jet via electron decay mode at s = 7TeV in CMS@LHC U BHAWANDEEP and SUMAN B BERI for CMS Collaboration
More informationJet Properties in Pb-Pb collisions at ALICE
Jet Properties in Pb-Pb collisions at ALICE Oliver Busch University of sukuba Heidelberg University for the ALICE collaboration Oliver Busch LHC Seminar 5/216 1 Outline Introduction Jets in heavy-ion collisions
More informationReview of photon physics results at Quark Matter 2012
Review of photon physics results at Quark Matter 2012 Jet Gustavo Conesa Balbastre 1/28 Why photons? Direct thermal: Produced by the QGP Measure medium temperature R AA > 1, v 2 > 0 Direct prompt: QCD
More informationExperimental Overview on Heavy Flavor Production in Heavy Ion Collisions.
Experimental Overview on Heavy Flavor Production in Heavy Ion Collisions. Cesar L. da Silva 1, 1 Los Alamos National Lab - USA Abstract. The use of probes containing heavy quarks is one of the pillars
More informationFuture prospects of di-jet production at. forward rapidity constraining Δg(x) at low x in. polarized p+p collisions at RHIC
Future prospects of di-jet production at forward rapidity constraining Δg(x at low x in polarized p+p collisions at RHIC Bernd Surrow QCD Evolution Workshop - QCD! Santa Fe, NM, May, Bernd Surrow Outline
More informationHigh-p T Neutral Pion Production in Heavy Ion Collisions at SPS and RHIC
High- Neutral Pion Production in Heavy Ion Collisions at SPS and RHIC K. Reygers for the WA98 and the PHENIX collaboration Institut für Kernphysik der Universität Münster Wilhelm-Klemm-Str. 9, D-4849 Münster,
More informationarxiv:nucl-th/ v2 8 Jun 2006
Acta Phys. Hung. A / (2005) 000 000 HEAVY ION PHYSICS Strange quark collectivity of φ meson at RHIC arxiv:nucl-th/0510095v2 8 Jun 2006 J. H. Chen 1,2, Y. G. Ma 1,a, G. L. Ma 1,2, H. Z. Huang 1,3, X. Z.
More informationMeasurement of Inclusive Charged Jet Production in pp and Pb-Pb collisions at snn = 5.02 TeV with ALICE
1 Measurement of Inclusive Charged Jet Production in pp and Pb-Pb collisions at snn = 5.02 TeV with ALICE Hiroki Yokoyama for the ALICE collaboration LPSC, Université Grenoble-Alpes, CNRS/IN2P3 University
More informationAzimuthal distributions of high-pt direct and 0. at STAR
Azimuthal distributions of high-pt direct and 0 w.r.t reaction plane For the at STAR Ahmed Hamed Collaboration Hot Quarks 2010 La Londe les Maures, 21-26th June, 2010 Ahmed Hamed (Texas A&M University)
More informationGluons at high x in Nuclei at EIC
Gluons at high x in Nuclei at EIC in collaboration with: E. Chudakov, D. Higinbotham, C. Hyde, C. Weiss Jefferson Lab DNP 2015 Fall meeting, Santa Fe, NM Outline Motivation HERA and ZEUS experience EIC
More informationSTAR upgrade program and future physics
Journal of Physics: Conference Series OPEN ACCESS STAR upgrade program and future physics To cite this article: Yaping Wang and the Star Collaboration 2014 J. Phys.: Conf. Ser. 535 012022 View the article
More informationestar? Ernst Sichtermann, LBNL Many thanks to colleagues in STAR and outside
estar? Ernst Sichtermann, LBNL Many thanks to colleagues in STAR and outside RHIC Spin Mtg, Iowa May 21 Truly impressive proton data: HERA HERA Truly impressive proton data: Much less so for nuclear or
More informationSub-hadronic degrees of freedom in ultrarelativistic nuclear collisions at RHIC and beyond
Sub-hadronic degrees of freedom in ultrarelativistic nuclear collisions at RHIC and beyond Lawrence Berkeley National Laboratory Berkeley, US 1 Introduction: Heavy Ion Physics Today t = 5 10 17 sec T=1
More informationConference Report Mailing address: CMS CERN, CH-1211 GENEVA 23, Switzerland
CMS CR /8 he Compact Muon Solenoid Experiment Conference Report Mailing address: CMS CERN, CH- GENEVA 3, Switzerland 3/7/ Nuclear modification factors from the CMS experiment arxiv:7.3v [hep-ex] 3 Jul
More informationMeasurement of W-boson production in p-pb collisions at the LHC with ALICE
Measurement of W-boson production in p-pb collisions at the LHC with ALICE for the ALICE Collaboration University of Cape Town Rondebosch, Cape Town, 7700, South Africa ithemba Laboratory of Accelerator
More informationMultiplicity dependence of charged pion, kaon, and (anti)proton production at large transverse momentum in p-pb collisions at 5.
[1] Multiplicity dependence of charged pion, kaon, and (anti)proton production at large transverse momentum in p-pb collisions at 5.02 ATeV Gyula Bencedi (Wigner RCP, Hungary) on behalf of the ALICE Collaboration
More informationMeasurements of charm and beauty proton structure functions F2 c c and F2 b b at HERA
Measurements of charm and beauty proton structure functions F c c and F b b at HERA Vladimir Chekelian MPI for Physics, Germany E-mail: shekeln@mail.desy.de Inclusive charm and beauty production is studied
More informationarxiv: v1 [nucl-ex] 14 Oct 2013
Charged Jets in Minimum Bias p-pb Collisions at snn = 5.02 TeV with ALICE arxiv:1310.3612v1 [nucl-ex] 14 Oct 2013 for the ALICE collaboration Westfälische Wilhelms-Universität Münster, Germany E-mail:
More informationSTUDY OF D AND D PRODUCTION IN B AND C JETS, WITH THE DELPHI DETECTOR C. BOURDARIOS
STUDY OF D AND D PRODUCTION IN B AND C JETS, WITH THE DETECTOR C. BOURDARIOS Université de Paris Sud, Laboratoire de l Accélérateur Linéaire, Bât. 2, B.P. 34, FR-91898 ORSAY CEDEX E-mail: claire.bourdarios@cern.ch
More information